There are 5 worlds in kabbalah, representing 5 levels of the soul: yechida, chaya, neshama, ruach and nefesh. They correspond to the 5 worlds of Creation: Adam Kadmon, Atzilut, Beriah, Yetzirah and Assiyah. AK is the interface between the Superior Intelligence and the created realm. The Malkuth of any partzuf becomes the Keter of the lower one, therefore the Malkuth of AK becomes the Keter of Atzilut represented by Yeshua in the level of souls. When Yeshua said ‘I and the Father are One’ he meant that he was the highest point of the created beings, so therefore the Keter of Atzilut and at the same time the Malkuth of Adam Kadmon, i.e. the S.I. as it interfaces with created beings. Beyond AK there are obviously higher levels of Divinity that do not pertain to creation but to the S.I. beyond any conception or manifestation, thus in order to be able to be approached and perceived as G-d, i.e. to interact with created beings, He therefore facilitated this intermediary level of Adam Kadmon between He and the 4 lower worlds ABYA that correspond to the Divine Name YKVK, and this AK is the Father that Yeshua is identifying with, not with the essential S.I. beyond any possible conception or manifestation, but G-d as can be perceived and interacted with by the created beings at the level of Adam Kadmon or Yechida of the soul. In kabbalah terms the keter is the Crown meaning it’s just above the head/body but not part of it. We can only enter said space and interact with G-d through Torah and mitzvot and we are to then exit it and bring back the beneficence to the lower realms in order to spread the so-called Divine Light to all of creation.